The most common form of toilets without a doubt are water toilets. For reasons which are self-evident, these cannot be used for certain application areas and in certain places, for example holiday cottages and boats. Other types of toilets have been developed for these, such as earth closets, freezer toilets and electric toilets, for example. Recently these types of toilets have also come into fashion on account of environmental aspects. Many places and urban districts do not permit water toilets to be connected up to the sewerage system on account of treatment plant capacity and groundwater resources. Of the alternative toilets, electric toilets offer the absolute minimum of waste products.
Electric toilets function so that they are arranged with a receptacle under a protective lid, into which receptacle a liquid-resistant paper bag is placed. When one has relieved oneself into this and "flushes", i.e. activates the device by stepping on a pedal for example, the receptacle is opened and the waste drops down into a combustion chamber placed under the receptacle. When the pedal is then released, the receptacle and a lid for the combustion chamber are closed. Heating coils are then activated in the combustion chamber, which burns the waste. An evacuation facility from the combustion chamber arranged with a fan sucks out the combustion gases and routes them out into a ventilation pipe. Following combustion, only a little ash remains in the bottom of the combustion chamber.
The electric toilets which are on the market have a number of disadvantages. Due to the fact that the combustion chamber is designed as a vertical cylinder and the electric coils are arranged in the top edge of the cylinder up by the lid, the coils do not provide uniform radiant heat in the bottom of the combustion chamber, but "pockets" are obtained with poorer heat, especially around the edges between the bottom and the side. Other disadvantages are that the top part of the bag has a tendency to get caught between the lid and the edge of the combustion chamber, in which case the bag does not collapse when it drops down but stands up. This also applies if the foot slips off the pedal during "flushing". If combustion is then commenced, the combustion chamber is not closed, but flames may emerge between the lid and the opening.
Another serious disadvantage is the design of the evacuation device. If the power for the electric toilet is lost while combustion is in progress, the power for the suction fan is also lost. This means that the flue gases from the hot feces are no longer sucked out but end up in the space where the toilet is located, with a powerful stench as a result. Furthermore, a nasty-smelling coating is obtained on the fan, especially when this is arranged in the path of the flue gases.
From the safety aspect, the electric toilets on the market are not optimun, as they permit flushing to occur when the protective lid is raised. This causes children for example possibly to get the idea into their head of stepping on the pedal with the protective lid open, in the event of which the receptacle and the combustion chamber are opened, with a major risk of burns. In addition, these electric toilets are disposed with a spring system for suspension of the upper and lower part of the combustion chamber, which springs lose their elasticity with time on account of the heat and even break, which on the one hand causes a gap between the parts of the combustion chamber and on the other means that the toilet cannot be used.
A further disadvantage is that the electric toilets on the market do not have any spillage protection in case a person does not know how the toilet is to be used and urinates in the receptacle without having first placed a bag therein. The urine then runs down through the receptacle and into the interior of the toilet with major cleaning problems as a result.
Further disadvantages are that the locking of the ash box, i.e. the lower part of the combustion chamber, includes springs which draw this up towards the upper part of the combustion chamber. These lose their elasticity after a relatively short time, largely due to the heat from the combustion, at which a gap is created between the ash box and the upper part with a strong odor as a result.